1. Field of the Invention
The present invention relates to an array substrate and a display panel having the array substrate. More particularly, the present invention relates to an array substrate having an enhanced aperture ratio and enhanced light transmittance and a display panel having the array substrate.
2. Description of the Related Art
In order to realize wide viewing angles in liquid crystal display (LCD) devices, in-plane switching (IPS) mode LCD devices and fringe-field switching (FFS) mode LCD devices have been developed. In the IPS mode LCD device, a pixel electrode and a common electrode are formed on a single substrate so that a horizontal electric field (or a transverse electric field) formed between the two electrodes can control a liquid crystal director. In a IPS mode LCD device, liquid crystal molecules rotate in a plane substantially parallel to an alignment layer of a substrate. Therefore, the difference in refractive index anisotropy is small when viewed by a viewer, and a liquid crystal layer includes liquid crystal molecules having two rotation directions opposite to each other when viewed from a cross-sectional view which compensates a phase difference of light to realize a wide viewing angle.
A FFS mode LCD device uses a transverse electric field and is substantially identical with a IPS mode LCD device in terms of how the liquid crystal molecules are arranged using the transverse electric field. However, the pixel electrode and the common electrode are formed on different layers in a FFS mode LCD device, so that a FFS mode LCD device arranges liquid crystal molecules using both a horizontal electric field and a vertical electric field.
A FFS mode LCD device arranges liquid crystal molecules using the vertical electric field, so that the light transmittance of a FFS mode LCD device is superior to that of a IPS mode LCD device. Moreover, liquid crystal molecules of a FFS mode LCD device are moved in a substantially horizontal direction, so that the viewing angle of a FFS mode LCD device is substantially identical to that of a IPS mode LCD device. Furthermore, the aperture ratio of a FFS mode LCD device is superior to that of a IPS mode LCD device.